/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------------
 * DatasetUtilities.java
 * ---------------------
 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Andrzej Porebski (bug fix);
 *                   Jonathan Nash (bug fix);
 *                   Richard Atkinson;
 *                   Andreas Schroeder;
 *
 * $Id: DatasetUtilities.java,v 1.1 2008/03/09 02:11:00 administrator Exp $
 *
 * Changes (from 18-Sep-2001)
 * --------------------------
 * 18-Sep-2001 : Added standard header and fixed DOS encoding problem (DG);
 * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG);
 * 15-Nov-2001 : Moved to package com.jrefinery.data.* in the JCommon class 
 *               library (DG);
 *               Changed to handle null values from datasets (DG);
 *               Bug fix (thanks to Andrzej Porebski) - initial value now set 
 *               to positive or negative infinity when iterating (DG);
 * 22-Nov-2001 : Datasets with containing no data now return null for min and 
 *               max calculations (DG);
 * 13-Dec-2001 : Extended to handle HighLowDataset and IntervalXYDataset (DG);
 * 15-Feb-2002 : Added getMinimumStackedRangeValue() and 
 *               getMaximumStackedRangeValue() (DG);
 * 28-Feb-2002 : Renamed Datasets.java --> DatasetUtilities.java (DG);
 * 18-Mar-2002 : Fixed bug in min/max domain calculation for datasets that 
 *               implement the CategoryDataset interface AND the XYDataset 
 *               interface at the same time.  Thanks to Jonathan Nash for the 
 *               fix (DG);
 * 23-Apr-2002 : Added getDomainExtent() and getRangeExtent() methods (DG);
 * 13-Jun-2002 : Modified range measurements to handle 
 *               IntervalCategoryDataset (DG);
 * 12-Jul-2002 : Method name change in DomainInfo interface (DG);
 * 30-Jul-2002 : Added pie dataset summation method (DG);
 * 01-Oct-2002 : Added a method for constructing an XYDataset from a Function2D
 *               instance (DG);
 * 24-Oct-2002 : Amendments required following changes to the CategoryDataset 
 *               interface (DG);
 * 18-Nov-2002 : Changed CategoryDataset to TableDataset (DG);
 * 04-Mar-2003 : Added isEmpty(XYDataset) method (DG);
 * 05-Mar-2003 : Added a method for creating a CategoryDataset from a 
 *               KeyedValues instance (DG);
 * 15-May-2003 : Renamed isEmpty --> isEmptyOrNull (DG);
 * 25-Jun-2003 : Added limitPieDataset methods (RA);
 * 26-Jun-2003 : Modified getDomainExtent() method to accept null datasets (DG);
 * 27-Jul-2003 : Added getStackedRangeExtent(TableXYDataset data) (RA);
 * 18-Aug-2003 : getStackedRangeExtent(TableXYDataset data) now handles null 
 *               values (RA);
 * 02-Sep-2003 : Added method to check for null or empty PieDataset (DG);
 * 18-Sep-2003 : Fix for bug 803660 (getMaximumRangeValue for 
 *               CategoryDataset) (DG);
 * 20-Oct-2003 : Added getCumulativeRangeExtent() method (DG);
 * 09-Jan-2003 : Added argument checking code to the createCategoryDataset() 
 *               method (DG);
 * 23-Mar-2004 : Fixed bug in getMaximumStackedRangeValue() method (DG);
 * 31-Mar-2004 : Exposed the extent iteration algorithms to use one of them and 
 *               applied noninstantiation pattern (AS);
 * 11-May-2004 : Renamed getPieDatasetTotal --> calculatePieDatasetTotal (DG);
 * 15-Jul-2004 : Switched getX() with getXValue() and getY() with getYValue();
 * 24-Aug-2004 : Added argument checks to createCategoryDataset() method (DG);
 * 04-Oct-2004 : Renamed ArrayUtils --> ArrayUtilities (DG);
 * 06-Oct-2004 : Renamed findDomainExtent() --> findDomainBounds(),
 *               findRangeExtent() --> findRangeBounds() (DG);
 * 07-Jan-2005 : Renamed findStackedRangeExtent() --> findStackedRangeBounds(),
 *               findCumulativeRangeExtent() --> findCumulativeRangeBounds(),
 *               iterateXYRangeExtent() --> iterateXYRangeBounds(), 
 *               removed deprecated methods (DG);
 * 03-Feb-2005 : The findStackedRangeBounds() methods now return null for 
 *               empty datasets (DG);
 * 03-Mar-2005 : Moved createNumberArray() and createNumberArray2D() methods
 *               from DatasetUtilities --> DataUtilities (DG);
 * 22-Sep-2005 : Added new findStackedRangeBounds() method that takes base
 *               argument (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 15-Mar-2007 : Added calculateStackTotal() method (DG);
 * 
 */

package org.mii.safeguard_v1.tools.jfreechart.utilities;

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;

import org.jfree.data.DomainInfo;
import org.jfree.data.KeyToGroupMap;
import org.jfree.data.KeyedValues;
import org.jfree.data.Range;
import org.jfree.data.RangeInfo;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.data.category.IntervalCategoryDataset;
import org.jfree.data.function.Function2D;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;
import org.jfree.data.xy.IntervalXYDataset;
import org.jfree.data.xy.OHLCDataset;
import org.jfree.data.xy.TableXYDataset;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.util.ArrayUtilities;
import org.mii.safeguard_v1.tools.jfreechart.model.ListMapArrayModel;

/**
 * A collection of useful static methods relating to datasets.
 */
public final class DatasetUtilities {

	/**
	 * Private constructor for non-instanceability.
	 */
	private DatasetUtilities() {
		// now try to instantiate this ;-)
	}

	/**
	 * Calculates the total of all the values in a {@link PieDataset}. If the
	 * dataset contains negative or <code>null</code> values, they are
	 * ignored.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The total.
	 */
	public static double calculatePieDatasetTotal(PieDataset dataset) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		List keys = dataset.getKeys();
		double totalValue = 0;
		Iterator iterator = keys.iterator();
		while (iterator.hasNext()) {
			Comparable current = (Comparable) iterator.next();
			if (current != null) {
				Number value = dataset.getValue(current);
				double v = 0.0;
				if (value != null) {
					v = value.doubleValue();
				}
				if (v > 0) {
					totalValue = totalValue + v;
				}
			}
		}
		return totalValue;
	}

	/**
	 * Creates a pie dataset from a table dataset by taking all the values for a
	 * single row.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param rowKey
	 *            the row key.
	 * 
	 * @return A pie dataset.
	 */
	public static PieDataset createPieDatasetForRow(CategoryDataset dataset,
			Comparable rowKey) {
		int row = dataset.getRowIndex(rowKey);
		return createPieDatasetForRow(dataset, row);
	}

	/**
	 * Creates a pie dataset from a table dataset by taking all the values for a
	 * single row.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param row
	 *            the row (zero-based index).
	 * 
	 * @return A pie dataset.
	 */
	public static PieDataset createPieDatasetForRow(CategoryDataset dataset,
			int row) {
		DefaultPieDataset result = new DefaultPieDataset();
		int columnCount = dataset.getColumnCount();
		for (int current = 0; current < columnCount; current++) {
			Comparable columnKey = dataset.getColumnKey(current);
			result.setValue(columnKey, dataset.getValue(row, current));
		}
		return result;
	}

	/**
	 * Creates a pie dataset from a table dataset by taking all the values for a
	 * single column.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param columnKey
	 *            the column key.
	 * 
	 * @return A pie dataset.
	 */
	public static PieDataset createPieDatasetForColumn(CategoryDataset dataset,
			Comparable columnKey) {
		int column = dataset.getColumnIndex(columnKey);
		return createPieDatasetForColumn(dataset, column);
	}

	/**
	 * Creates a pie dataset from a {@link CategoryDataset} by taking all the
	 * values for a single column.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param column
	 *            the column (zero-based index).
	 * 
	 * @return A pie dataset.
	 */
	public static PieDataset createPieDatasetForColumn(CategoryDataset dataset,
			int column) {
		DefaultPieDataset result = new DefaultPieDataset();
		int rowCount = dataset.getRowCount();
		for (int i = 0; i < rowCount; i++) {
			Comparable rowKey = dataset.getRowKey(i);
			result.setValue(rowKey, dataset.getValue(i, column));
		}
		return result;
	}

	/**
	 * Creates a new pie dataset based on the supplied dataset, but modified by
	 * aggregating all the low value items (those whose value is lower than the
	 * <code>percentThreshold</code>) into a single item with the key
	 * "Other".
	 * 
	 * @param source
	 *            the source dataset (<code>null</code> not permitted).
	 * @param key
	 *            a new key for the aggregated items (<code>null</code> not
	 *            permitted).
	 * @param minimumPercent
	 *            the percent threshold.
	 * 
	 * @return The pie dataset with (possibly) aggregated items.
	 */
	public static PieDataset createConsolidatedPieDataset(PieDataset source,
			Comparable key, double minimumPercent) {
		return DatasetUtilities.createConsolidatedPieDataset(source, key,
				minimumPercent, 2);
	}

	/**
	 * Creates a new pie dataset based on the supplied dataset, but modified by
	 * aggregating all the low value items (those whose value is lower than the
	 * <code>percentThreshold</code>) into a single item. The aggregated
	 * items are assigned the specified key. Aggregation only occurs if there
	 * are at least <code>minItems</code> items to aggregate.
	 * 
	 * @param source
	 *            the source dataset (<code>null</code> not permitted).
	 * @param key
	 *            the key to represent the aggregated items.
	 * @param minimumPercent
	 *            the percent threshold (ten percent is 0.10).
	 * @param minItems
	 *            only aggregate low values if there are at least this many.
	 * 
	 * @return The pie dataset with (possibly) aggregated items.
	 */
	public static PieDataset createConsolidatedPieDataset(PieDataset source,
			Comparable key, double minimumPercent, int minItems) {

		DefaultPieDataset result = new DefaultPieDataset();
		double total = DatasetUtilities.calculatePieDatasetTotal(source);

		// Iterate and find all keys below threshold percentThreshold
		List keys = source.getKeys();
		ArrayList otherKeys = new ArrayList();
		Iterator iterator = keys.iterator();
		while (iterator.hasNext()) {
			Comparable currentKey = (Comparable) iterator.next();
			Number dataValue = source.getValue(currentKey);
			if (dataValue != null) {
				double value = dataValue.doubleValue();
				if (value / total < minimumPercent) {
					otherKeys.add(currentKey);
				}
			}
		}

		// Create new dataset with keys above threshold percentThreshold
		iterator = keys.iterator();
		double otherValue = 0;
		while (iterator.hasNext()) {
			Comparable currentKey = (Comparable) iterator.next();
			Number dataValue = source.getValue(currentKey);
			if (dataValue != null) {
				if (otherKeys.contains(currentKey)
						&& otherKeys.size() >= minItems) {
					// Do not add key to dataset
					otherValue += dataValue.doubleValue();
				} else {
					// Add key to dataset
					result.setValue(currentKey, dataValue);
				}
			}
		}
		// Add other category if applicable
		if (otherKeys.size() >= minItems) {
			result.setValue(key, otherValue);
		}
		return result;
	}

	/**
	 * Creates a {@link CategoryDataset} that contains a copy of the data in an
	 * array (instances of <code>Double</code> are created to represent the
	 * data items).
	 * <p>
	 * Row and column keys are created by appending 0, 1, 2, ... to the supplied
	 * prefixes.
	 * 
	 * @param rowKeyPrefix
	 *            the row key prefix.
	 * @param columnKeyPrefix
	 *            the column key prefix.
	 * @param data
	 *            the data.
	 * 
	 * @return The dataset.
	 */
	public static CategoryDataset createCategoryDataset(String rowKeyPrefix,
			String columnKeyPrefix, double[][] data) {

		DefaultCategoryDataset result = new DefaultCategoryDataset();
		for (int r = 0; r < data.length; r++) {
			String rowKey = rowKeyPrefix + (r + 1);
			for (int c = 0; c < data[r].length; c++) {
				String columnKey = columnKeyPrefix + (c + 1);
				result.addValue(new Double(data[r][c]), rowKey, columnKey);
			}
		}
		return result;

	}
	
	public static CategoryDataset createCategoryDataset(Hashtable rowKeyPrefix,
			Hashtable columnKeyPrefix, double[][] data) {

		DefaultCategoryDataset result = new DefaultCategoryDataset();
		int i = 1;
		for (Enumeration e = rowKeyPrefix.keys(); e.hasMoreElements() ;i++){
			String rowKey = e.nextElement().toString()+(i);
			//String rowKey = e.nextElement().toString()+(i);
			int j = 1;
			/*for(int k = 1;k<=columnKeyPrefix.size();k++)
			{
				columnKeyPrefix.containsValue(k);
				String columnKey = columnKeyPrefix.get(k).toString();
				result.addValue(new Double(data[i][j]), rowKey,columnKey );
			}*/
			/*这种方法 不能够保证hashtable中的数据是按照顺序取出来的（当时存储在hashtable中时，顺序就已经变了）*/
				//j = columnKeyPrefix.size();
			 	for (Enumeration f = columnKeyPrefix.keys(); f.hasMoreElements() ;j++){
				String columnKey = f.nextElement().toString();
				result.addValue(new Double(data[i][j]), rowKey,columnKey );
			}
			
		}
		return result;
		
	}
		
		public static CategoryDataset createCategoryDataset(String[] rowKeyPrefix,
				String[] columnKeyPrefix, int[] data) {
			
			DefaultCategoryDataset result = new DefaultCategoryDataset();
			int i = 1;
			for (int c = 0; c < data.length; c++) {
				result.addValue(new Integer(data[c]), rowKeyPrefix[c], columnKeyPrefix[c]);
			}
			return result;
	}

	/**
	 * Creates a {@link CategoryDataset} that contains a copy of the data in an
	 * array.
	 * <p>
	 * Row and column keys are created by appending 0, 1, 2, ... to the supplied
	 * prefixes.
	 * 
	 * @param rowKeyPrefix
	 *            the row key prefix.
	 * @param columnKeyPrefix
	 *            the column key prefix.
	 * @param data
	 *            the data.
	 * 
	 * @return The dataset.
	 */
	public static CategoryDataset createCategoryDataset(String rowKeyPrefix,
			String columnKeyPrefix, Number[][] data) {

		DefaultCategoryDataset result = new DefaultCategoryDataset();
		for (int r = 0; r < data.length; r++) {
			String rowKey = rowKeyPrefix + (r + 1);
			for (int c = 0; c < data[r].length; c++) {
				String columnKey = columnKeyPrefix + (c + 1);
				result.addValue(data[r][c], rowKey, columnKey);
			}
		}
		return result;

	}

	/**
	 * Creates a {@link CategoryDataset} that contains a copy of the data in an
	 * array (instances of <code>Double</code> are created to represent the
	 * data items).
	 * <p>
	 * Row and column keys are taken from the supplied arrays.
	 * 
	 * @param rowKeys
	 *            the row keys (<code>null</code> not permitted).
	 * @param columnKeys
	 *            the column keys (<code>null</code> not permitted).
	 * @param data
	 *            the data.
	 * 
	 * @return The dataset.
	 */
	public static CategoryDataset createCategoryDataset(Comparable[] rowKeys,
			Comparable[] columnKeys, double[][] data) {

		// check arguments...
		if (rowKeys == null) {
			throw new IllegalArgumentException("Null 'rowKeys' argument.");
		}
		if (columnKeys == null) {
			throw new IllegalArgumentException("Null 'columnKeys' argument.");
		}
		if (ArrayUtilities.hasDuplicateItems(rowKeys)) {
			throw new IllegalArgumentException("Duplicate items in 'rowKeys'.");
		}
		if (ArrayUtilities.hasDuplicateItems(columnKeys)) {
			throw new IllegalArgumentException(
					"Duplicate items in 'columnKeys'.");
		}
		if (rowKeys.length != data.length) {
			throw new IllegalArgumentException(
					"The number of row keys does not match the number of rows in "
							+ "the data array.");
		}
		int columnCount = 0;
		for (int r = 0; r < data.length; r++) {
			columnCount = Math.max(columnCount, data[r].length);
		}
		if (columnKeys.length != columnCount) {
			throw new IllegalArgumentException(
					"The number of column keys does not match the number of "
							+ "columns in the data array.");
		}

		// now do the work...
		DefaultCategoryDataset result = new DefaultCategoryDataset();
		for (int r = 0; r < data.length; r++) {
			Comparable rowKey = rowKeys[r];
			for (int c = 0; c < data[r].length; c++) {
				Comparable columnKey = columnKeys[c];
				result.addValue(new Double(data[r][c]), rowKey, columnKey);
			}
		}
		return result;

	}

	public static CategoryDataset createCategoryDataset(
			List<ListMapArrayModel> rowKeys,
			List<ListMapArrayModel> columnKeys, double[][] data) {
		String[] rows = new String[rowKeys.size()];
		String[] cols = new String[columnKeys.size()];
		for (int i = 0; i < rowKeys.size(); i++) {
			rows[i] = rowKeys.get(i).getContent();
		}
		for (int i = 0; i < columnKeys.size(); i++) {
			cols[i] = columnKeys.get(i).getContent();
		}

		// check arguments...
		if (rowKeys == null) {
			throw new IllegalArgumentException("Null 'rows' argument.");
		}
		if (columnKeys == null) {
			throw new IllegalArgumentException("Null 'cols' argument.");
		}
		if (ArrayUtilities.hasDuplicateItems(rows)) {
			throw new IllegalArgumentException("Duplicate items in 'rows'.");
		}
		if (ArrayUtilities.hasDuplicateItems(cols)) {
			throw new IllegalArgumentException("Duplicate items in 'cols'.");
		}
		if (rows.length != data.length) {
			throw new IllegalArgumentException(
					"The number of row keys does not match the number of rows in "
							+ "the data array.");
		}
		int columnCount = 0;
		for (int r = 0; r < data.length; r++) {
			columnCount = Math.max(columnCount, data[r].length);
		}
		if (cols.length != columnCount) {
			throw new IllegalArgumentException(
					"The number of column keys does not match the number of "
							+ "columns in the data array.");
		}

		// now do the work...
		DefaultCategoryDataset result = new DefaultCategoryDataset();
		for (int r = 0; r < data.length; r++) {
			Comparable rowKey = rows[r];
			for (int c = 0; c < data[r].length; c++) {
				Comparable columnKey = cols[c];
				result.addValue(new Double(data[r][c]), rowKey, columnKey);
			}
		}
		return result;

	}

	/**
	 * Creates a {@link CategoryDataset} by copying the data from the supplied
	 * {@link KeyedValues} instance.
	 * 
	 * @param rowKey
	 *            the row key (<code>null</code> not permitted).
	 * @param rowData
	 *            the row data (<code>null</code> not permitted).
	 * 
	 * @return A dataset.
	 */
	public static CategoryDataset createCategoryDataset(Comparable rowKey,
			KeyedValues rowData) {

		if (rowKey == null) {
			throw new IllegalArgumentException("Null 'rowKey' argument.");
		}
		if (rowData == null) {
			throw new IllegalArgumentException("Null 'rowData' argument.");
		}
		DefaultCategoryDataset result = new DefaultCategoryDataset();
		for (int i = 0; i < rowData.getItemCount(); i++) {
			result.addValue(rowData.getValue(i), rowKey, rowData.getKey(i));
		}
		return result;

	}

	/**
	 * Creates an {@link XYDataset} by sampling the specified function over a
	 * fixed range.
	 * 
	 * @param f
	 *            the function (<code>null</code> not permitted).
	 * @param start
	 *            the start value for the range.
	 * @param end
	 *            the end value for the range.
	 * @param samples
	 *            the number of sample points (must be > 1).
	 * @param seriesKey
	 *            the key to give the resulting series (<code>null</code> not
	 *            permitted).
	 * 
	 * @return A dataset.
	 */
	public static XYDataset sampleFunction2D(Function2D f, double start,
			double end, int samples, Comparable seriesKey) {

		if (f == null) {
			throw new IllegalArgumentException("Null 'f' argument.");
		}
		if (seriesKey == null) {
			throw new IllegalArgumentException("Null 'seriesKey' argument.");
		}
		if (start >= end) {
			throw new IllegalArgumentException("Requires 'start' < 'end'.");
		}
		if (samples < 2) {
			throw new IllegalArgumentException("Requires 'samples' > 1");
		}

		XYSeries series = new XYSeries(seriesKey);
		double step = (end - start) / samples;
		for (int i = 0; i <= samples; i++) {
			double x = start + (step * i);
			series.add(x, f.getValue(x));
		}
		XYSeriesCollection collection = new XYSeriesCollection(series);
		return collection;

	}

	/**
	 * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
	 * and <code>false</code> otherwise.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> permitted).
	 * 
	 * @return A boolean.
	 */
	public static boolean isEmptyOrNull(PieDataset dataset) {

		if (dataset == null) {
			return true;
		}

		int itemCount = dataset.getItemCount();
		if (itemCount == 0) {
			return true;
		}

		for (int item = 0; item < itemCount; item++) {
			Number y = dataset.getValue(item);
			if (y != null) {
				double yy = y.doubleValue();
				if (yy > 0.0) {
					return false;
				}
			}
		}

		return true;

	}

	/**
	 * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
	 * and <code>false</code> otherwise.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> permitted).
	 * 
	 * @return A boolean.
	 */
	public static boolean isEmptyOrNull(CategoryDataset dataset) {

		if (dataset == null) {
			return true;
		}

		int rowCount = dataset.getRowCount();
		int columnCount = dataset.getColumnCount();
		if (rowCount == 0 || columnCount == 0) {
			return true;
		}

		for (int r = 0; r < rowCount; r++) {
			for (int c = 0; c < columnCount; c++) {
				if (dataset.getValue(r, c) != null) {
					return false;
				}

			}
		}

		return true;

	}

	/**
	 * Returns <code>true</code> if the dataset is empty (or <code>null</code>),
	 * and <code>false</code> otherwise.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> permitted).
	 * 
	 * @return A boolean.
	 */
	public static boolean isEmptyOrNull(XYDataset dataset) {

		boolean result = true;

		if (dataset != null) {
			for (int s = 0; s < dataset.getSeriesCount(); s++) {
				if (dataset.getItemCount(s) > 0) {
					result = false;
					continue;
				}
			}
		}

		return result;

	}

	/**
	 * Returns the range of values in the domain (x-values) of a dataset.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range of values (possibly <code>null</code>).
	 */
	public static Range findDomainBounds(XYDataset dataset) {
		return findDomainBounds(dataset, true);
	}

	/**
	 * Returns the range of values in the domain (x-values) of a dataset.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param includeInterval
	 *            determines whether or not the x-interval is taken into account
	 *            (only applies if the dataset is an {@link IntervalXYDataset}).
	 * 
	 * @return The range of values (possibly <code>null</code>).
	 */
	public static Range findDomainBounds(XYDataset dataset,
			boolean includeInterval) {

		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}

		Range result = null;
		// if the dataset implements DomainInfo, life is easier
		if (dataset instanceof DomainInfo) {
			DomainInfo info = (DomainInfo) dataset;
			result = info.getDomainBounds(includeInterval);
		} else {
			result = iterateDomainBounds(dataset, includeInterval);
		}
		return result;

	}

	/**
	 * Iterates over the items in an {@link XYDataset} to find the range of
	 * x-values.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range iterateDomainBounds(XYDataset dataset) {
		return iterateDomainBounds(dataset, true);
	}

	/**
	 * Iterates over the items in an {@link XYDataset} to find the range of
	 * x-values.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param includeInterval
	 *            a flag that determines, for an IntervalXYDataset, whether the
	 *            x-interval or just the x-value is used to determine the
	 *            overall range.
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range iterateDomainBounds(XYDataset dataset,
			boolean includeInterval) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		double minimum = Double.POSITIVE_INFINITY;
		double maximum = Double.NEGATIVE_INFINITY;
		int seriesCount = dataset.getSeriesCount();
		double lvalue;
		double uvalue;
		if (includeInterval && dataset instanceof IntervalXYDataset) {
			IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
			for (int series = 0; series < seriesCount; series++) {
				int itemCount = dataset.getItemCount(series);
				for (int item = 0; item < itemCount; item++) {
					lvalue = intervalXYData.getStartXValue(series, item);
					uvalue = intervalXYData.getEndXValue(series, item);
					minimum = Math.min(minimum, lvalue);
					maximum = Math.max(maximum, uvalue);
				}
			}
		} else {
			for (int series = 0; series < seriesCount; series++) {
				int itemCount = dataset.getItemCount(series);
				for (int item = 0; item < itemCount; item++) {
					lvalue = dataset.getXValue(series, item);
					uvalue = lvalue;
					minimum = Math.min(minimum, lvalue);
					maximum = Math.max(maximum, uvalue);
				}
			}
		}
		if (minimum > maximum) {
			return null;
		} else {
			return new Range(minimum, maximum);
		}
	}

	/**
	 * Returns the range of values in the range for the dataset.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range findRangeBounds(CategoryDataset dataset) {
		return findRangeBounds(dataset, true);
	}

	/**
	 * Returns the range of values in the range for the dataset.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param includeInterval
	 *            a flag that determines whether or not the y-interval is taken
	 *            into account.
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range findRangeBounds(CategoryDataset dataset,
			boolean includeInterval) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		Range result = null;
		if (dataset instanceof RangeInfo) {
			RangeInfo info = (RangeInfo) dataset;
			result = info.getRangeBounds(includeInterval);
		} else {
			result = iterateCategoryRangeBounds(dataset, includeInterval);
		}
		return result;
	}

	/**
	 * Returns the range of values in the range for the dataset. This method is
	 * the partner for the {@link #findDomainBounds(XYDataset)} method.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range findRangeBounds(XYDataset dataset) {
		return findRangeBounds(dataset, true);
	}

	/**
	 * Returns the range of values in the range for the dataset. This method is
	 * the partner for the {@link #findDomainBounds(XYDataset)} method.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param includeInterval
	 *            a flag that determines whether or not the y-interval is taken
	 *            into account.
	 * 
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range findRangeBounds(XYDataset dataset,
			boolean includeInterval) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		Range result = null;
		if (dataset instanceof RangeInfo) {
			RangeInfo info = (RangeInfo) dataset;
			result = info.getRangeBounds(includeInterval);
		} else {
			result = iterateXYRangeBounds(dataset);
		}
		return result;
	}

	/**
	 * Iterates over the data item of the category dataset to find the range
	 * bounds.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param includeInterval
	 *            a flag that determines whether or not the y-interval is taken
	 *            into account.
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range iterateCategoryRangeBounds(CategoryDataset dataset,
			boolean includeInterval) {
		double minimum = Double.POSITIVE_INFINITY;
		double maximum = Double.NEGATIVE_INFINITY;
		boolean interval = includeInterval
				&& dataset instanceof IntervalCategoryDataset;
		int rowCount = dataset.getRowCount();
		int columnCount = dataset.getColumnCount();
		for (int row = 0; row < rowCount; row++) {
			for (int column = 0; column < columnCount; column++) {
				Number lvalue;
				Number uvalue;
				if (interval) {
					IntervalCategoryDataset icd = (IntervalCategoryDataset) dataset;
					lvalue = icd.getStartValue(row, column);
					uvalue = icd.getEndValue(row, column);
				} else {
					lvalue = dataset.getValue(row, column);
					uvalue = lvalue;
				}
				if (lvalue != null) {
					minimum = Math.min(minimum, lvalue.doubleValue());
				}
				if (uvalue != null) {
					maximum = Math.max(maximum, uvalue.doubleValue());
				}
			}
		}
		if (minimum == Double.POSITIVE_INFINITY) {
			return null;
		} else {
			return new Range(minimum, maximum);
		}
	}

	/**
	 * Iterates over the data item of the xy dataset to find the range bounds.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range (possibly <code>null</code>).
	 */
	public static Range iterateXYRangeBounds(XYDataset dataset) {
		double minimum = Double.POSITIVE_INFINITY;
		double maximum = Double.NEGATIVE_INFINITY;
		int seriesCount = dataset.getSeriesCount();
		for (int series = 0; series < seriesCount; series++) {
			int itemCount = dataset.getItemCount(series);
			for (int item = 0; item < itemCount; item++) {
				double lvalue;
				double uvalue;
				if (dataset instanceof IntervalXYDataset) {
					IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
					lvalue = intervalXYData.getStartYValue(series, item);
					uvalue = intervalXYData.getEndYValue(series, item);
				} else if (dataset instanceof OHLCDataset) {
					OHLCDataset highLowData = (OHLCDataset) dataset;
					lvalue = highLowData.getLowValue(series, item);
					uvalue = highLowData.getHighValue(series, item);
				} else {
					lvalue = dataset.getYValue(series, item);
					uvalue = lvalue;
				}
				if (!Double.isNaN(lvalue)) {
					minimum = Math.min(minimum, lvalue);
				}
				if (!Double.isNaN(uvalue)) {
					maximum = Math.max(maximum, uvalue);
				}
			}
		}
		if (minimum == Double.POSITIVE_INFINITY) {
			return null;
		} else {
			return new Range(minimum, maximum);
		}
	}

	/**
	 * Finds the minimum domain (or X) value for the specified dataset. This is
	 * easy if the dataset implements the {@link DomainInfo} interface (a good
	 * idea if there is an efficient way to determine the minimum value).
	 * Otherwise, it involves iterating over the entire data-set.
	 * <p>
	 * Returns <code>null</code> if all the data values in the dataset are
	 * <code>null</code>.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The minimum value (possibly <code>null</code>).
	 */
	public static Number findMinimumDomainValue(XYDataset dataset) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		Number result = null;
		// if the dataset implements DomainInfo, life is easy
		if (dataset instanceof DomainInfo) {
			DomainInfo info = (DomainInfo) dataset;
			return new Double(info.getDomainLowerBound(true));
		} else {
			double minimum = Double.POSITIVE_INFINITY;
			int seriesCount = dataset.getSeriesCount();
			for (int series = 0; series < seriesCount; series++) {
				int itemCount = dataset.getItemCount(series);
				for (int item = 0; item < itemCount; item++) {

					double value;
					if (dataset instanceof IntervalXYDataset) {
						IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
						value = intervalXYData.getStartXValue(series, item);
					} else {
						value = dataset.getXValue(series, item);
					}
					if (!Double.isNaN(value)) {
						minimum = Math.min(minimum, value);
					}

				}
			}
			if (minimum == Double.POSITIVE_INFINITY) {
				result = null;
			} else {
				result = new Double(minimum);
			}
		}

		return result;
	}

	/**
	 * Returns the maximum domain value for the specified dataset. This is easy
	 * if the dataset implements the {@link DomainInfo} interface (a good idea
	 * if there is an efficient way to determine the maximum value). Otherwise,
	 * it involves iterating over the entire data-set. Returns <code>null</code>
	 * if all the data values in the dataset are <code>null</code>.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The maximum value (possibly <code>null</code>).
	 */
	public static Number findMaximumDomainValue(XYDataset dataset) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		Number result = null;
		// if the dataset implements DomainInfo, life is easy
		if (dataset instanceof DomainInfo) {
			DomainInfo info = (DomainInfo) dataset;
			return new Double(info.getDomainUpperBound(true));
		}

		// hasn't implemented DomainInfo, so iterate...
		else {
			double maximum = Double.NEGATIVE_INFINITY;
			int seriesCount = dataset.getSeriesCount();
			for (int series = 0; series < seriesCount; series++) {
				int itemCount = dataset.getItemCount(series);
				for (int item = 0; item < itemCount; item++) {

					double value;
					if (dataset instanceof IntervalXYDataset) {
						IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
						value = intervalXYData.getEndXValue(series, item);
					} else {
						value = dataset.getXValue(series, item);
					}
					if (!Double.isNaN(value)) {
						maximum = Math.max(maximum, value);
					}
				}
			}
			if (maximum == Double.NEGATIVE_INFINITY) {
				result = null;
			} else {
				result = new Double(maximum);
			}

		}

		return result;
	}

	/**
	 * Returns the minimum range value for the specified dataset. This is easy
	 * if the dataset implements the {@link RangeInfo} interface (a good idea if
	 * there is an efficient way to determine the minimum value). Otherwise, it
	 * involves iterating over the entire data-set. Returns <code>null</code>
	 * if all the data values in the dataset are <code>null</code>.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The minimum value (possibly <code>null</code>).
	 */
	public static Number findMinimumRangeValue(CategoryDataset dataset) {

		// check parameters...
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}

		// work out the minimum value...
		if (dataset instanceof RangeInfo) {
			RangeInfo info = (RangeInfo) dataset;
			return new Double(info.getRangeLowerBound(true));
		}

		// hasn't implemented RangeInfo, so we'll have to iterate...
		else {
			double minimum = Double.POSITIVE_INFINITY;
			int seriesCount = dataset.getRowCount();
			int itemCount = dataset.getColumnCount();
			for (int series = 0; series < seriesCount; series++) {
				for (int item = 0; item < itemCount; item++) {
					Number value;
					if (dataset instanceof IntervalCategoryDataset) {
						IntervalCategoryDataset icd = (IntervalCategoryDataset) dataset;
						value = icd.getStartValue(series, item);
					} else {
						value = dataset.getValue(series, item);
					}
					if (value != null) {
						minimum = Math.min(minimum, value.doubleValue());
					}
				}
			}
			if (minimum == Double.POSITIVE_INFINITY) {
				return null;
			} else {
				return new Double(minimum);
			}

		}

	}

	/**
	 * Returns the minimum range value for the specified dataset. This is easy
	 * if the dataset implements the {@link RangeInfo} interface (a good idea if
	 * there is an efficient way to determine the minimum value). Otherwise, it
	 * involves iterating over the entire data-set. Returns <code>null</code>
	 * if all the data values in the dataset are <code>null</code>.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The minimum value (possibly <code>null</code>).
	 */
	public static Number findMinimumRangeValue(XYDataset dataset) {

		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}

		// work out the minimum value...
		if (dataset instanceof RangeInfo) {
			RangeInfo info = (RangeInfo) dataset;
			return new Double(info.getRangeLowerBound(true));
		}

		// hasn't implemented RangeInfo, so we'll have to iterate...
		else {
			double minimum = Double.POSITIVE_INFINITY;
			int seriesCount = dataset.getSeriesCount();
			for (int series = 0; series < seriesCount; series++) {
				int itemCount = dataset.getItemCount(series);
				for (int item = 0; item < itemCount; item++) {

					double value;
					if (dataset instanceof IntervalXYDataset) {
						IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
						value = intervalXYData.getStartYValue(series, item);
					} else if (dataset instanceof OHLCDataset) {
						OHLCDataset highLowData = (OHLCDataset) dataset;
						value = highLowData.getLowValue(series, item);
					} else {
						value = dataset.getYValue(series, item);
					}
					if (!Double.isNaN(value)) {
						minimum = Math.min(minimum, value);
					}

				}
			}
			if (minimum == Double.POSITIVE_INFINITY) {
				return null;
			} else {
				return new Double(minimum);
			}

		}

	}

	/**
	 * Returns the maximum range value for the specified dataset. This is easy
	 * if the dataset implements the {@link RangeInfo} interface (a good idea if
	 * there is an efficient way to determine the maximum value). Otherwise, it
	 * involves iterating over the entire data-set. Returns <code>null</code>
	 * if all the data values are <code>null</code>.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The maximum value (possibly <code>null</code>).
	 */
	public static Number findMaximumRangeValue(CategoryDataset dataset) {

		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}

		// work out the minimum value...
		if (dataset instanceof RangeInfo) {
			RangeInfo info = (RangeInfo) dataset;
			return new Double(info.getRangeUpperBound(true));
		}

		// hasn't implemented RangeInfo, so we'll have to iterate...
		else {

			double maximum = Double.NEGATIVE_INFINITY;
			int seriesCount = dataset.getRowCount();
			int itemCount = dataset.getColumnCount();
			for (int series = 0; series < seriesCount; series++) {
				for (int item = 0; item < itemCount; item++) {
					Number value;
					if (dataset instanceof IntervalCategoryDataset) {
						IntervalCategoryDataset icd = (IntervalCategoryDataset) dataset;
						value = icd.getEndValue(series, item);
					} else {
						value = dataset.getValue(series, item);
					}
					if (value != null) {
						maximum = Math.max(maximum, value.doubleValue());
					}
				}
			}
			if (maximum == Double.NEGATIVE_INFINITY) {
				return null;
			} else {
				return new Double(maximum);
			}

		}

	}

	/**
	 * Returns the maximum range value for the specified dataset. This is easy
	 * if the dataset implements the {@link RangeInfo} interface (a good idea if
	 * there is an efficient way to determine the maximum value). Otherwise, it
	 * involves iterating over the entire data-set. Returns <code>null</code>
	 * if all the data values are <code>null</code>.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The maximum value (possibly <code>null</code>).
	 */
	public static Number findMaximumRangeValue(XYDataset dataset) {

		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}

		// work out the minimum value...
		if (dataset instanceof RangeInfo) {
			RangeInfo info = (RangeInfo) dataset;
			return new Double(info.getRangeUpperBound(true));
		}

		// hasn't implemented RangeInfo, so we'll have to iterate...
		else {

			double maximum = Double.NEGATIVE_INFINITY;
			int seriesCount = dataset.getSeriesCount();
			for (int series = 0; series < seriesCount; series++) {
				int itemCount = dataset.getItemCount(series);
				for (int item = 0; item < itemCount; item++) {
					double value;
					if (dataset instanceof IntervalXYDataset) {
						IntervalXYDataset intervalXYData = (IntervalXYDataset) dataset;
						value = intervalXYData.getEndYValue(series, item);
					} else if (dataset instanceof OHLCDataset) {
						OHLCDataset highLowData = (OHLCDataset) dataset;
						value = highLowData.getHighValue(series, item);
					} else {
						value = dataset.getYValue(series, item);
					}
					if (!Double.isNaN(value)) {
						maximum = Math.max(maximum, value);
					}
				}
			}
			if (maximum == Double.NEGATIVE_INFINITY) {
				return null;
			} else {
				return new Double(maximum);
			}

		}

	}

	/**
	 * Returns the minimum and maximum values for the dataset's range
	 * (y-values), assuming that the series in one category are stacked.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range (<code>null</code> if the dataset contains no
	 *         values).
	 */
	public static Range findStackedRangeBounds(CategoryDataset dataset) {
		return findStackedRangeBounds(dataset, 0.0);
	}

	/**
	 * Returns the minimum and maximum values for the dataset's range
	 * (y-values), assuming that the series in one category are stacked.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param base
	 *            the base value for the bars.
	 * 
	 * @return The range (<code>null</code> if the dataset contains no
	 *         values).
	 */
	public static Range findStackedRangeBounds(CategoryDataset dataset,
			double base) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		Range result = null;
		double minimum = Double.POSITIVE_INFINITY;
		double maximum = Double.NEGATIVE_INFINITY;
		int categoryCount = dataset.getColumnCount();
		for (int item = 0; item < categoryCount; item++) {
			double positive = base;
			double negative = base;
			int seriesCount = dataset.getRowCount();
			for (int series = 0; series < seriesCount; series++) {
				Number number = dataset.getValue(series, item);
				if (number != null) {
					double value = number.doubleValue();
					if (value > 0.0) {
						positive = positive + value;
					}
					if (value < 0.0) {
						negative = negative + value;
						// '+', remember value is negative
					}
				}
			}
			minimum = Math.min(minimum, negative);
			maximum = Math.max(maximum, positive);
		}
		if (minimum <= maximum) {
			result = new Range(minimum, maximum);
		}
		return result;

	}

	/**
	 * Returns the minimum and maximum values for the dataset's range
	 * (y-values), assuming that the series in one category are stacked.
	 * 
	 * @param dataset
	 *            the dataset.
	 * @param map
	 *            a structure that maps series to groups.
	 * 
	 * @return The value range (<code>null</code> if the dataset contains no
	 *         values).
	 */
	public static Range findStackedRangeBounds(CategoryDataset dataset,
			KeyToGroupMap map) {

		Range result = null;
		if (dataset != null) {

			// create an array holding the group indices...
			int[] groupIndex = new int[dataset.getRowCount()];
			for (int i = 0; i < dataset.getRowCount(); i++) {
				groupIndex[i] = map.getGroupIndex(map.getGroup(dataset
						.getRowKey(i)));
			}

			// minimum and maximum for each group...
			int groupCount = map.getGroupCount();
			double[] minimum = new double[groupCount];
			double[] maximum = new double[groupCount];

			int categoryCount = dataset.getColumnCount();
			for (int item = 0; item < categoryCount; item++) {
				double[] positive = new double[groupCount];
				double[] negative = new double[groupCount];
				int seriesCount = dataset.getRowCount();
				for (int series = 0; series < seriesCount; series++) {
					Number number = dataset.getValue(series, item);
					if (number != null) {
						double value = number.doubleValue();
						if (value > 0.0) {
							positive[groupIndex[series]] = positive[groupIndex[series]]
									+ value;
						}
						if (value < 0.0) {
							negative[groupIndex[series]] = negative[groupIndex[series]]
									+ value;
							// '+', remember value is negative
						}
					}
				}
				for (int g = 0; g < groupCount; g++) {
					minimum[g] = Math.min(minimum[g], negative[g]);
					maximum[g] = Math.max(maximum[g], positive[g]);
				}
			}
			for (int j = 0; j < groupCount; j++) {
				result = Range.combine(result,
						new Range(minimum[j], maximum[j]));
			}
		}
		return result;

	}

	/**
	 * Returns the minimum value in the dataset range, assuming that values in
	 * each category are "stacked".
	 * 
	 * @param dataset
	 *            the dataset.
	 * 
	 * @return The minimum value.
	 */
	public static Number findMinimumStackedRangeValue(CategoryDataset dataset) {

		Number result = null;
		if (dataset != null) {
			double minimum = 0.0;
			int categoryCount = dataset.getRowCount();
			for (int item = 0; item < categoryCount; item++) {
				double total = 0.0;

				int seriesCount = dataset.getColumnCount();
				for (int series = 0; series < seriesCount; series++) {
					Number number = dataset.getValue(series, item);
					if (number != null) {
						double value = number.doubleValue();
						if (value < 0.0) {
							total = total + value;
							// '+', remember value is negative
						}
					}
				}
				minimum = Math.min(minimum, total);

			}
			result = new Double(minimum);
		}
		return result;

	}

	/**
	 * Returns the maximum value in the dataset range, assuming that values in
	 * each category are "stacked".
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> permitted).
	 * 
	 * @return The maximum value (possibly <code>null</code>).
	 */
	public static Number findMaximumStackedRangeValue(CategoryDataset dataset) {

		Number result = null;

		if (dataset != null) {
			double maximum = 0.0;
			int categoryCount = dataset.getColumnCount();
			for (int item = 0; item < categoryCount; item++) {
				double total = 0.0;
				int seriesCount = dataset.getRowCount();
				for (int series = 0; series < seriesCount; series++) {
					Number number = dataset.getValue(series, item);
					if (number != null) {
						double value = number.doubleValue();
						if (value > 0.0) {
							total = total + value;
						}
					}
				}
				maximum = Math.max(maximum, total);
			}
			result = new Double(maximum);
		}

		return result;

	}

	/**
	 * Returns the minimum and maximum values for the dataset's range, assuming
	 * that the series are stacked.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range ([0.0, 0.0] if the dataset contains no values).
	 */
	public static Range findStackedRangeBounds(TableXYDataset dataset) {
		return findStackedRangeBounds(dataset, 0.0);
	}

	/**
	 * Returns the minimum and maximum values for the dataset's range, assuming
	 * that the series are stacked, using the specified base value.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * @param base
	 *            the base value.
	 * 
	 * @return The range (<code>null</code> if the dataset contains no
	 *         values).
	 */
	public static Range findStackedRangeBounds(TableXYDataset dataset,
			double base) {
		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}
		double minimum = base;
		double maximum = base;
		for (int itemNo = 0; itemNo < dataset.getItemCount(); itemNo++) {
			double positive = base;
			double negative = base;
			int seriesCount = dataset.getSeriesCount();
			for (int seriesNo = 0; seriesNo < seriesCount; seriesNo++) {
				double y = dataset.getYValue(seriesNo, itemNo);
				if (!Double.isNaN(y)) {
					if (y > 0.0) {
						positive += y;
					} else {
						negative += y;
					}
				}
			}
			if (positive > maximum) {
				maximum = positive;
			}
			if (negative < minimum) {
				minimum = negative;
			}
		}
		if (minimum <= maximum) {
			return new Range(minimum, maximum);
		} else {
			return null;
		}
	}

	/**
	 * Calculates the total for the y-values in all series for a given item
	 * index.
	 * 
	 * @param dataset
	 *            the dataset.
	 * @param item
	 *            the item index.
	 * 
	 * @return The total.
	 * 
	 * @since 1.0.5
	 */
	public static double calculateStackTotal(TableXYDataset dataset, int item) {
		double total = 0.0;
		int seriesCount = dataset.getSeriesCount();
		for (int s = 0; s < seriesCount; s++) {
			double value = dataset.getYValue(s, item);
			if (!Double.isNaN(value)) {
				total = total + value;
			}
		}
		return total;
	}

	/**
	 * Calculates the range of values for a dataset where each item is the
	 * running total of the items for the current series.
	 * 
	 * @param dataset
	 *            the dataset (<code>null</code> not permitted).
	 * 
	 * @return The range.
	 * 
	 * @see #findRangeBounds(CategoryDataset)
	 */
	public static Range findCumulativeRangeBounds(CategoryDataset dataset) {

		if (dataset == null) {
			throw new IllegalArgumentException("Null 'dataset' argument.");
		}

		boolean allItemsNull = true; // we'll set this to false if there is
										// at
		// least one non-null data item...
		double minimum = 0.0;
		double maximum = 0.0;
		for (int row = 0; row < dataset.getRowCount(); row++) {
			double runningTotal = 0.0;
			for (int column = 0; column < dataset.getColumnCount() - 1; column++) {
				Number n = dataset.getValue(row, column);
				if (n != null) {
					allItemsNull = false;
					double value = n.doubleValue();
					runningTotal = runningTotal + value;
					minimum = Math.min(minimum, runningTotal);
					maximum = Math.max(maximum, runningTotal);
				}
			}
		}
		if (!allItemsNull) {
			return new Range(minimum, maximum);
		} else {
			return null;
		}

	}

}
